(1) Summary of the Invention
The present invention relates to a method for controlling Poa trivialis by infecting it with a Xanthomonas campestris pathovar which does not infect non-weed grasses. In particular, the present invention relates to the use of Xanthomonas campestris PT1 to suppress or kill the weedy grass.
(2) Prior Art
Bacteria infect grasses causing the grasses to be suppressed or killed. These infections have been known in other parts of the world as important problems for the maintenance of desirable grasses. This method of biological control eliminates the need for herbicides which are relatively toxic chemicals to people and the environment.
A bacterial infection of Toronto creeping bentgrass which is used on golf putting greens is described by Roberts, D. L., et al. in Plant Disease 65, 1014-1015 (1981); Roberts, K. D., et al., Plant Disease 66, 804-806 (1982); Roberts, D. L., et al., Scanning Electron Microscopy IV, 1719-1722 (1983). The bacterium was identified as a Xanthomonas campestris by Roberts, D. L. in Phytopathology 73, 810 and 74, 813 (1984). The solution to the problem was treatment of the infection with oxytetracycline, an antibiotic. A disease of Poa annua L. was also described by Roberts, D. L. in Phytopathology 75 1289 (1985). U.S. Pat. No. 5,077,045 describes using a strain of Xanthomonas to control Poa annua.
The diseases caused by Xanthomonas campestris pathovars have also been studied by others and have been found to be selectively pathogenic to particular grass species. Elgi, T., et al. Phytopath Z. 82, 111-121 (1975) first characterized a bacterial infection of cut grasses. Other publications include: Wilkins, P. W., et al. Plant Path 26, 99 (1977); DeCleene, M., et al., Parasitica 37(1) 29-34 (1981); Leyns, F., et al., Parasitica 37, 131-133 (1981); Van Den Mooter, M. et al., Med Fac Landbouww Rijksuniv. Gent 46/3, 787-792 (1981); Van Den Mooter, M., et al Parasitica 37 (1):23-28 (1981); Proc. Fifth Int. Conf. Path Bact, Calif. 332-333 (1981); Egli, T. et al. Phytopath Z. 104, 138-150 (1982); and Leyns et al. Med. Fac. Landbouww Rijksuniv Gent. 47/3 1079-1081 (1982).